Hvac authentication system and method

ABSTRACT

An authentication method and system for an HVAC system are provided. Embodiments of the present disclosure generally relate to an access-control or authentication system for an HVAC system, in which access to certain functions of the HVAC system is conditioned on a user performing certain basic operational instructions for the HVAC system in a provided sequence, thereby providing evidence that the user has authorization to access and operate the HVAC system wirelessly.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/888,718, entitled “HVAC Authentication System and Method,” filed onMay 30, 2020, which claims priority to and benefit of U.S. ProvisionalPatent Application No. 62/855,787, entitled “HVAC Authentication Systemand Method,” filed on May 31, 2019.

BACKGROUND

This section is intended to introduce the reader to various aspects ofthe art that may be related to various aspects of the presentlydescribed embodiments—to help facilitate a better understanding of thoseembodiments. Accordingly, it should be understood that these statementsare to be read in this light, and not as admissions of prior art.

Modern residential and industrial customers expect indoor spaces to beclimate controlled. In general, heating, ventilation, andair-conditioning (“HVAC”) systems circulate an indoor space's air overlow-temperature (for cooling) or high-temperature (for heating) sources,thereby adjusting the indoor space's air temperature. HVAC systemsgenerate these low- and high-temperature sources by, among othertechniques, taking advantage of a well-known physical principle: a fluidtransitioning from gas to liquid releases heat, while a fluidtransitioning from liquid to gas absorbs heat.

Within a typical HVAC system, a fluid refrigerant circulates through aclosed loop of tubing that uses compressors and other flow-controldevices to manipulate the refrigerant's flow and pressure, causing therefrigerant to cycle between the liquid and gas phases. Generally, thesephase transitions occur within the HVAC's heat exchangers, which arepart of the closed loop and designed to transfer heat between thecirculating refrigerant and flowing ambient air. As would be expected,the heat exchanger providing heating or cooling to theclimate-controlled space or structure is described adjectivally as being“indoors,” and the heat exchanger transferring heat with the surroundingoutdoor environment is described as being “outdoors.”

Typically, the operation of the HVAC system is managed by a controllerthat “calls” for the activation or deactivation of various componentswithin the system. For example, the controller may be a thermostat thatcan be operated to place a call to the system to heat or cool the indoorair, or to call for activation of a fan (blower) to drive circulation ofthe indoor air. More specifically, the controller may place a call tothe control circuitry of the HVAC system that, in turn, manages thefunctions of the HVAC system's components to produce the resultrequested by the call.

Property owners or dwellers may contact a professional technician toinstall or maintain the property's HVAC system. To provide effectiveservice, the technician may need to access certain functions (settings,stored history, stored data, firmware) of the HVAC system which, incertain instances, is done through a wireless communication system asdescribed in U.S. patent application Ser. No. 15/043,134, which entitledis “Systems and Methods for Air Temperature Control Using a Target TimeBased Control Plan,” was filed on Feb. 12, 2016, by GoodmanManufacturing Company, L.P., and is herein incorporated by reference inits entirety.

It would be advantageous to provide systems and methods that improve thesecurity surrounding access to the HVAC system's various functions.

SUMMARY

Certain aspects of some embodiments disclosed herein are set forthbelow. It should be understood that these aspects are presented merelyto provide the reader with a brief summary of certain forms theinvention might take and that these aspects are not intended to limitthe scope of the invention. Indeed, the invention may encompass avariety of aspects that may not be set forth below.

Embodiments of the present disclosure generally relate to anaccess-control or authentication system for an HVAC system, in whichaccess to certain functions of the HVAC system is conditioned on a userperforming certain basic operational instructions for the HVAC system ina provided sequence, thereby providing evidence that the user hasauthorization to access and operate the HVAC system wirelessly.

Various refinements of the features noted above may exist in relation tovarious aspects of the present embodiments. Further features may also beincorporated in these various aspects as well. These refinements andadditional features may exist individually or in any combination. Forinstance, various features discussed below in relation to one or more ofthe illustrated embodiments may be incorporated into any of theabove-described aspects of the present disclosure alone or in anycombination. Again, the brief summary presented above is intended onlyto familiarize the reader with certain aspects and contexts of someembodiments without limitation to the claimed subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of certain embodimentswill become better understood when the following detailed description isread with reference to the accompanying drawings in which likecharacters represent like parts throughout the drawings, wherein:

FIG. 1 illustrates schematically an HVAC system for heating and coolingindoor spaces within a structure, in accordance with an embodiment ofthe present disclosure;

FIG. 2 illustrates schematically a communication network for an HVACsystem, in accordance with an embodiment of the present invention;

FIG. 3 illustrates schematically an authentication network for pairing aportable device with an HVAC system, in accordance with an embodiment ofthe present invention;

FIGS. 4, 5, 6, and 7 illustrate screenshots of software that may be onthe portable device for communicating with the HVAC system, inaccordance with an embodiment of the present invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, all features of an actual implementation may not bedescribed. It should be appreciated that in the development of any suchactual implementation, as in any engineering or design project, numerousimplementation-specific decisions must be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one implementation toanother. Moreover, it should be appreciated that such a developmenteffort might be complex and time consuming, but would nevertheless be aroutine undertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

When introducing elements of various embodiments, the articles “a,”“an,” “the,” and “said” are intended to mean that there are one or moreof the elements. The terms “comprising,” “including,” and “having” areintended to be inclusive and mean that there may be additional elementsother than the listed elements.

Turning now the figures, FIG. 1 illustrates an HVAC system 10 inaccordance with one embodiment. As depicted, the system 10 providesheating and cooling for a residential structure 12. But the conceptsdisclosed herein are applicable to a myriad of heating and coolingsituations, including industrial and commercial settings.

The described HVAC system 10 divides into two primary portions: Theoutdoor unit 14, which mainly comprises components 15 (e.g., flowcontrol devices for circulating refrigerant, valves, compressors, or anoutdoor heat exchanger) for transferring heat with the environmentoutside the structure 12; and the indoor unit 16, which mainly comprisescomponents for transferring heat with the air inside the structure 12.In the illustrated structure, a ducted indoor unit 16 provides heatingand cooling to various indoor spaces 18.

The ducted indoor unit 16 has an air-handling unit (or AHU) 20 thatprovides airflow circulation, which in the illustrated embodiment drawsambient indoor air via returns 22, passes that air over one or moreheating/cooling elements (i.e., sources of heating or cooling), and thenroutes that conditioned air, whether heated or cooled, back to thevarious climate-controlled spaces 18 through ducts or ductworks 24—whichare relatively large pipes that may be rigid or flexible. A blower 26provides the motivational force to circulate the ambient air through thereturns 22, AHU, and ducts 24.

As shown, the ducted indoor unit 16 is a heating and cooling system thathas multiple elements. A gas furnace 28, which may be located downstream(in terms of airflow) of the blower 26, combusts natural gas to produceheat in furnace tubes (not shown) that coil through the furnace. Thesefurnace tubes act as a heating element for the ambient indoor air beingpushed out of the blower 26, over the furnace tubes, and into the ducts24.

To cool the indoor space 18, the indoor air may be guided over theindoor heat exchanger 30, with the heat in the ambient air being drawninto the refrigerant circulating through the indoor heat exchanger 30.The blower, gas furnace, and indoor heat exchanger may be packaged as anintegrated AHU, or those components may be modular. Moreover, it isenvisaged that the positions of the gas furnace and indoor heatexchangers or blower can be reversed or rearranged.

The indoor heat exchanger 30—which in this embodiment for the ductedindoor unit 16 is an A-coil, as it known in the industry—acts as acooling element that removes heat from the structure by manipulating thepressure and flow of refrigerant circulating within and between theA-coil and the outdoor unit 14 via refrigerant lines 32. But, byreversing the flow of the refrigerant, the indoor heat exchanger 30 canact as a “heat pump” by transferring heat to the circulating ambient airand, in turn, heating the indoor space 18.

The HVAC system 10 may be operated or adjusted by a controller, such asthermostat 34, which acts as a user interface to the HVAC system via awired connection 36 or a wireless connection (e.g., wi-fi, LAN,Bluetooth, cellular signal). In the illustrated embodiment, thethermostat 34 is a “24-volt thermostat” that can send signals to, butcannot receive signals from, the indoor unit 20. But in alternateembodiments, the thermostat and the HVAC system may be “communicating”such that the HVAC system (and components thereof) and the thermostatare capable of sending and receiving information and signals to and fromone another.

FIG. 2 schematically illustrates exemplary communication pathwaysamongst a “24 volt” thermostat 34 and the HVAC system 10. In theillustrated embodiment, the “24 volt” thermostat 34 may send a callsignal over wire 36 to the HVAC system 10, to activate a certainfunction on the HVAC system. For example, the thermostat may send a “Y”call that instructs the HVAC system to perform cooling, to cool theindoor space 18. The thermostat may also send a “W” or “G” call thatinstructs the HVAC perform heating or activate the blower 26,respectively. Alternatively, the calls may be placed manually by thetechnician bypassing the thermostat and causing the circuit to close,thereby providing the desired call.

That call is communicated 38—typically by wire 36 but potentiallywirelessly—to a control board 40 that is located in the HVAC system 10,in this case in the indoor unit 16. The control board 40 processes thecall and then coordinates the operation of various components within theHVAC system. For example, the control board 40 may instruct componentsin the outdoor unit 16 to begin circulation of refrigerant to effectcooling. Or the control board may instruct the gas furnace to activateto effect heating. Further still, the control board 40 may instruct theblower 26 to circulate air. To assist in these commands, the controlboard 40 may include memory 42 that contains operating instruction basedon the call provided. Moreover, the outdoor unit may include its owncircuitry to facilitate operation of the HVAC system's components.

In the illustrated embodiment, indoor unit includes a communicationdevice 44 that facilitates user communication with the HVAC systemindependent of the thermostat. For example, the communication device 44may be a transceiver (e.g., Bluetooth transceiver, wi-fi transceiver,cellular transceiver) that is connected by wire to the HVAC system'scontrol board 40 but can communicate wirelessly with the user. (It isalso envisaged that the communication device could communicate with thecontrol board 40 wirelessly.)

In certain instances, it may be beneficial for a service technician tocommunicate with the HVAC system. For example, the service technicianmay wish to place the HVAC system into a test mode, access data orinformation stored on the HVAC system, operate the HVAC system, orupdate the HVAC system's firmware. One way to accomplish this is tocreate a wired connection between the HVAC system and a portable devicethe technician may have. Alternatively, that connection can be madewirelessly.

As illustrated in FIG. 3 , the technician may have a portable device 46(e.g., laptop, cellular phone, tablet) that can assist in the diagnosisand service of the HVAC system. And this portable device 46 (which maybe connected to the Internet) may have the ability to communicatewirelessly over a wireless protocol, such as Bluetooth, wi-fi protocols,or a cellular signal. Since both the indoor unit 16 and the portabledevice 46 are capable of wireless communication, the portable device mayconnect to the HVAC system wirelessly, allowing the technician tocommunicate with the HVAC system independent of the thermostat. Theportable device may have software (e.g., app, programming) that providesan HMI that makes it easier to manage on the portable device theinformation transmitted to or received from the HVAC system.Advantageously, this wireless communication makes it easier for thetechnician, who may have to connect to an awkwardly located mechanicalconnector located on the HVAC system if the connection were made througha wire.

In certain instances, it is desirable to permit wireless connection tothe HVAC system only when the service technician or user can provideevidence of possession and control of the HVAC system. That is, thetechnician can present proof-of-possession for the HVAC system. SomeHVAC systems may use proximity-based security, in which the HVAC systemtransmits a low-power wireless signal during quiescent operation thatcan only be detected by the portable device is in close proximity (1-2meters) to the indoor unit. If the portable device 46 is close enough tothe indoor unit, the HVAC system may pair (and thus communicate) withthe device and increase the wireless signal strength, allowing thetechnician to maintain communication between the portable device and theHVAC system while the technician is servicing components that may belocated further away from the indoor unit. Moreover, once paired, theHVAC system may allow the portable device to access additionalfunctionality on the HVAC system beyond just the pairing function, suchadditional functionality allowing, for example, the technician tooperate the HVAC system, place the HVAC system into a test mode, oraccess historical information or update the firmware located on the HVACsystem—all through the portable device.

For further security, the HVAC system may still employ this initialproximity-based pairing but provide an additional layer of security toaccess the additional functions. Upon intial pairing with the portabledevice, the control board 40 may generate a three-digit code that isdisplayed on a seven-segment display 48 located in the indoor unit. Thetechnician must then enter the three-digit code into his or her portabledevice, which is then communicated to the control board, to unlock theadditional functionality of the HVAC system that can be accessed fromthe portable device.

But, in certain instances, the indoor unit 16 may be installed in such away that it would be difficult for the technician to access or see thedisplay 48. For example, the display may be located access panel on theindoor unit. And even if a small window in the access panel is provided,it may be difficult to see the display. Or the indoor unit may beinstalled such that the window or access panel are difficult to get to.

As an alternative, the additional security—and proof-of-possession ofthe HVAC system—may be effected by requiring the technician to operatethe thermostat 34 to provide or remove a certain sequence of callsignals to the HVAC system. For example, to unlock the accessfunctionality of the HVAC unit through the portable device, thetechnician may first have to place the portable device in proximity withthe HVAC unit, to effect the initial paring. After that, the HVAC systemwill communicate a series of instructions to the portable device toallow the technician to unlock the additional functions.

As one example, the technician may be instructed to operate thethermostat such that it places a cooling call within three minutes ofthe initial pairing. Once the HVAC system detects a cooling call, thetechnician may then be instructed to operate the thermostat to removethe cooling call within two minutes. After that, the technician may beinstructed to place a heating call within three minutes of the coolingcall. Such a sequence of events is extremely unlikely to occur duringnormal operations, evidencing that the technician has access to theproperty and thus the authority to operate the HVAC system through theportable device.

As another example, the technician may be instructed, through theportable device's software once the device and the HVAC system areinitially paired, to remove all calls within five minutes, provide acooling call within eight minutes of removing all calls, and thenterminate the cooling call within two minutes after requesting thecooling call.

As yet another example, the technician may be instructed to remove allcalls within five minutes, place a blower call within eight minutes ofremoving all calls, and then remove the blower call within two minutesof placing the fan call.

Advantageously, the HVAC system may be programmed to rotate throughvarious permutations and combinations of the instructions each timepairing with a portable device is requested. Moreover, thisinstruction-based access may be “locked out” and disabled if multiplethe instructions are not properly performed within a prescribed amountof time (e.g., 60 minutes). And the instruction-based access may bereactivated by, for example, requiring the technician to use the codeprovided by the three-digit display.

The HVAC system may also have a time-based termination of access to theadditional functions for the portable device. For example, the HVACsystem may terminate the access to the portable device if it has notdetected communications with the portable device in 120 minutes.

Turning to FIGS. 4, 5 6, and 7, these figures illustrate a series ofscreen shots that may be displayed on the portable device during theauthentication process, demonstrating the underlying method. Forexample, when the portable device is brought into close proximity to theHVAC system's control board 40 or the transceiver 44, the portabledevice may display screen 50, which identifies the HVAC system theportable device is pairing with. At this point, the technician isprovided a choice of which method of authentication to use throughdisplay screen 51: The technician may select to use the code displayedby the indoor unit (screen portion 51A) or select to operate thethermostat 34 (screen portion 51B).

If the technician chooses to use the code, he or she will be directed tolocate the code on the indoor unit (screens 52 and 54) and then enterthe code displayed by indoor unit (image 56) into the portable device(screen 58), as illustrated in FIG. 5 .

Alternatively, as illustrated in FIG. 6 , if the technician chooses toperform the operations or tasks on the thermostat, he or she is taken toscreen 60. At this point, the technician is provided a first task orinstruction to perform on the HVAC system in a given amount of time.(Screen 62.) The technician is given a second task or instruction toperform once the first instruction has been completed, again in a givenamount of time. (Screen 64.) Then the final instruction is given (screen66), at which point the technician returns into close proximity to theindoor unit, such that the indoor unit can confirm to the portabledevice that the instructions have been performed.

By completing the plurality of instructions, the wireless transceivermay transition to a higher-power signal that maintains pairing with theportable device at a greater distance, and permits access to variousfunctions on the HVAC device. For example, as illustrated in FIG. 7 ,the HVAC system may permit the technician to view the HVAC system'sconfiguration (screen 68), or place various components of the HVACsystem into different run modes (screens 70 or 72).

While the aspects of the present disclosure may be susceptible tovarious modifications and alternative forms, specific embodiments havebeen shown by way of example in the drawings and have been described indetail herein. But it should be understood that the invention is notintended to be limited to the particular forms disclosed. Rather, theinvention is to cover all modifications, equivalents, and alternativesfalling within the spirit and scope of the invention as defined by thefollowing appended claims.

1. A method for authenticating a user for an HVAC system, the methodcomprising: effecting an initial proximity-based wireless communicationwith a wireless signal between a portable device and an indoor unit ofthe HVAC system, wherein the portable device is associated with a user;generating, via the HVAC system, a security code and displaying thesecurity code on the indoor unit; and permitting the portable device toaccess at least one additional function of the HVAC system if the HVACsystem detects the security code has been entered into the portabledevice.
 2. The method of claim 1, wherein the initial proximity-basedwireless communication is effected during quiescent operation of theHVAC system.
 3. The method of claim 1, wherein effecting the initialproximity-based wireless communication between the portable device andthe indoor unit of the HVAC system comprises: generating, with acommunication device that is part of the indoor unit of the HVAC system,the wireless signal at a low-power signal strength; and detecting thewireless signal with the portable device and accessing an initialproximity-based wireless communication pairing function of the HVACsystem to effect the initial wireless communication only if the portabledevice is in close physical proximity to, and thus the user has accessto, the indoor unit.
 4. The method of claim 3, wherein the wirelesssignal is a Bluetooth signal.
 5. The method of claim 3, wherein thelow-power signal strength requires the portable device to be within 1 or2 meters of the indoor unit.
 6. The method of claim 1, whereinpermitting the portable device to access at least one additionalfunction of the HVAC system comprises: pairing the HVAC system with theportable device for wireless communication if the HVAC system detectsthe security code has been entered into the portable device, thusproviding evidence that the user has possession and control of andauthorization to access and operate the HVAC system; and once paired,permitting the portable device to access the at least one additionalfunction of the HVAC system.
 7. The method of claim 6, whereinpermitting the portable device to access at least one additionalfunction of the HVAC system further comprises, once paired, increasing asignal strength of the wireless signal to allow the user to maintainwireless communication between the portable device and the HVAC systemoutside of a proximity range of the initial wireless communication. 8.The method of claim 3, further comprising outputting, by a control boardof the indoor unit, the security code to a display of the indoor unit ofthe HVAC system.
 9. The method of claim 8, wherein the display isseparate from a thermostat of the HVAC system.
 10. A method forauthenticating a user for an HVAC system of a structure, the methodcomprising: generating a wireless signal with the HVAC system at alow-power signal strength with a communication device that is part of anindoor unit of the HVAC system; detecting the wireless signal with aportable device carried by the user and effecting an initialproximity-based wireless communication pairing function between theportable device and the communication device only if the portable deviceis in close physical proximity to, and thus the user has access to, theindoor unit; providing, via the HVAC system: a security code, generatedby a control board of the indoor unit, for the user to enter into theportable device; and a plurality of instructions for operating the HVACsystem in a provided sequence to the portable device for the user toperform; pairing the HVAC system with the portable device for wirelesscommunication if the HVAC system detects an action by the user providingevidence that the user has possession and control of and authorizationto access and operate the HVAC system, the action comprising at leastone of: entering the security code into the portable device; orperforming the plurality of instructions; once paired, increasing thesignal strength of the wireless signal to allow the user to maintainwireless communication between the portable device and the HVAC systemwhile no longer in close proximity to the indoor unit; and once paired,permitting the portable device to access at least one additionalfunction of the HVAC system.
 11. The method of claim 10, wherein theaction comprises entering the security code into the portable deviceafter a failure to perform the plurality of instructions within aprescribed time interval.
 12. The method of claim 10, wherein the actioncomprises both entering the security code into the portable device andperforming a first plurality of instructions.
 13. The method of claim12, wherein the action further comprises entering the security codeafter incorrectly performing the first plurality of instructions. 14.The method of claim 12, wherein the action further comprises performinga second plurality of instructions after entering the security code. 15.The method of claim 14, wherein pairing the HVAC system with theportable device requires performing the second plurality of instructionswithin a prescribed time interval after entering the security code. 16.A system for authenticating a user for an HVAC system of a structure, aportable device being associated with the user, the system comprising:an indoor unit of the HVAC system comprising a control board and acommunication device, the indoor unit being operable to: generate afirst wireless signal having a low-power signal strength using thecommunication device; effect an initial proximity-based wirelesscommunication pairing function between the communication device and theportable device when the first wireless signal is detected by theportable device, only if the portable device is in close physicalproximity to, and thus the user has access to, the indoor unit; generatea security code; output the security code onto a display of the indoorunit; pair the HVAC system with the portable device for wirelesscommunication if the HVAC system detects the security code has beenentered into the portable device, thus providing evidence that the userhas possession and control of and authorization to access and operatethe HVAC system; once paired, provide a second wireless signal betweenthe communication device and the portable device to allow the user tomaintain wireless communication between the portable device and the HVACsystem while no longer in close proximity to the indoor unit; and oncepaired, permitting the portable device to access at least one additionalfunction of the HVAC system.
 17. The system of claim 16, wherein thefirst wireless signal is a Bluetooth signal, wherein the low-powersignal strength requires the portable device to be within 1 or 2 metersof the indoor unit.
 18. The system of claim 16, wherein the secondwireless signal has a second signal strength greater than the low-powersignal strength of the first wireless signal.
 19. The system of claim16, wherein the indoor unit is operable to generate the first wirelesssignal when the HVAC system is in a quiescent state.
 20. The system ofclaim 16, wherein the communication device is independent of athermostat of the HVAC system.